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Application programs should not, ideally, be exposed to details of data representation and storage. The DBMS provides an abstract view of the data that hides such details. [2] There are two types of data independence: physical and logical data independence. The data independence and operation independence together gives the feature of data ...
An anti-dependency occurs when an instruction requires a value that is later updated. A violation of an anti-dependency leads to a write-after-read (WAR) hazard.. In the following example, instruction 2 anti-depends on instruction 3 — the ordering of these instructions cannot be changed, nor can they be executed in parallel (possibly changing the instruction ordering), as this would affect ...
Databases and other data stores which treat the integrity of data as paramount often include the ability to handle transactions to maintain the integrity of data. A single transaction consists of one or more independent units of work, each reading and/or writing information to a database or other data store.
The ANSI-SPARC model however, never became a formal standard. No mainstream DBMS systems are fully based on it (they tend not to exhibit full physical independence or to prevent direct user access to the conceptual level), but the idea of logical data independence is widely adopted.
Formally, a "database" refers to a set of related data accessed through the use of a "database management system" (DBMS), which is an integrated set of computer software that allows users to interact with one or more databases and provides access to all of the data contained in the database (although restrictions may exist that limit access to particular data).
ODBC accomplishes DBMS independence by using an ODBC driver as a translation layer between the application and the DBMS. The application uses ODBC functions through an ODBC driver manager with which it is linked, and the driver passes the query to the DBMS. An ODBC driver can be thought of as analogous to a printer driver or other driver ...
using dynamic, table-driven logic, as opposed to logic embodied in previously compiled programs. The use of table-driven logic, i.e. behavior that is heavily dictated by the contents of a database, allows programs to be simpler and more flexible. This capability is a central feature of dynamic programming languages.
Codd's twelve rules [1] are a set of thirteen rules (numbered zero to twelve) proposed by Edgar F. Codd, a pioneer of the relational model for databases, designed to define what is required from a database management system in order for it to be considered relational, i.e., a relational database management system (RDBMS).